Method and apparatus for filling containers



D. EOLKIN Aug. 21, 1956 METHOD AND APPARATUS FOR FILLING CONTAINERS Filed Aug. 31, 1953 2 Sheets-Sheet l INVENTOR. DA VE EOL/(l/V ATTORNEY Aug, 21, 1956 D. EOLKIN 2,759,307

METHOD AND APPARATUS FOR FILLING CONTAINERS Filed Aug. 31, 1953 2 Sheets-Sheet 2 ATTORNEY United States Patent METHOD AND APPARATUS FOR FILLING CONTAINERS Dave Eolkin, San Lorenzo, Califi, assignor to Gerber Products Company, Fremont, Mich., a corporation of Michigan Application August 31, 1953, Serial No. 377,648 Claims. (Cl. 53-11) This invention relates to a new and useful method and apparatus for filling containers and relates more particularly to the displacement of air in the headspace of the container by a mixture of steam and nitrogen. In accordance with this invention the containers are packed and sealed with a minimum of oxygen in the headspace but with a vacuum which is materially reduced over that customarily employed.

One common method of packing containers is to create a high vacuum-4n excess of 29 inches of mercury-in the headspace. Such a high vacuum insures that a minimum of oxygen will be present thereby improving the appearance, flavor and nutritional value of the food packed. However, where a high vacuum is used a deleterious effect on the quality of the food may result. For example, products containing starch, such as puddings and soups, after having been cooked in a retort, undergo violent boiiing while they are cooling. This boiling ac tion causes break-down of starch and subsequent weeping of the final product. Chopped foods and the like, when subjected to a high vacuum are deleteriously aifected in that the gas cells in the pulp expand which causes a difference in density of the ingredients of the product and results in a layering eifect with the pulp rising to the top of the container.

On the other hand, if the vacuum is reduced, different deleterious effects result. Reduction in vacuum in accordance with conventional practice increases the quantity of oxygen present in the headspace and this causes discoloration of the product and afiects the taste and nutritional value thereof.

One expedient heretofore employed has been to reduce the amount of the headspace by over-filling the container. Losses by spillage and the consequent presence of the food product on the exterior of the container and the fact that the equipment must be cleaned frequently in order to remove the spilled material makes this expedient undesirable. In addition, over-filling of the jar reduces the profit on the sale of the product.

Still another method of packing containers is to fill the headspace with nitrogen, or other inert gas, but this method has certain inherent mechanical and economic disadvantages.

The present invention employs nitrogen but at the same time creates a vacuum in the container. This dual result is obtained by filling the headspace of the container with a mixture of steam and nitrogen. The steam condenses creating a vacuum and the nitrogen displaces the air which would otherwise be present. In this manner a lower vacuum may be employed without materially increasing the amount of oxygen in the headspace and the container may be filled to rated level, thereby eliminating the undesirable features of over-filling the containers.

Further, to reduce the amount of oxygen present in the headspace a flow of steam is introduced into the machine in which the caps are applied to the containers, the point of introduction being closely adjacent the portal through which the uncapped containers enter. The steam flows outward through the portal and thus prevents oxygen from entering. Further, to reduce the amount of oxygen which enters, a baflie in which is cut a silhouette of the jar is installed in the portal through which the containers enter. This materially reduces the space through which the air can enter, particularly when the jars are spaced closely together.

In standard operation of a standard steam flow, straight line container closing machine, steam at the rate of 5,000 cubic feet per hour is required to produce a vacuum of approximately 29 inches. In accordance with the present invention, a steam flow of cubic feet per hour and a nitrogen flow of cubic feet per hour are required to gether with steam at the portal at the rate of 1,950 cubic feet per hour. This results in a vacuum of 19.5 inches. The gases in the headspace at that degree of vacuum consist of 95% nitrogen and 4% oxygen. Thus, the equivalent of the vacuum in terms of the oxygen present in air is 29.4 inches. The result is that the vacuum is reduced 10 inches and yet the oxygen is reduced.

Other objects of the present invention will become apparent upon reading the following specification and referring to the accompanying drawings in which similar characters of reference represent corresponding parts in each of the several views.

In the drawings:

Fig. 1 is a longitudinal vertical section through the machine.

Fig. 2 is a view taken substantially along the line 2-2 of Fig. 1.

Fig. 3 is a schematic view similar to Fig. 1 showing the distribution of steam and nitrogen in the atmosphere in which the containers are capped, the prevalence of nitrogen being indicated by crosses and the presence of steam by dots.

The present invention is shown as applied to one of the standard forms of straight line machines used to cap glass containers with sheet metal caps. In such machines the headspace of the container is filled with steam, the air normally present being swept out by the steam flow, and after the cap is applied the steam condenses, creating a vacuum in the headspace. The details of such machinery constitute no part of this invention and accordingly reference is made to U. S. Patents No. 2,107,237 and No. 2,319,213 which illustrate the structure and describe its operation.

For the purpose of the present description of this invention, it is believed suflicient to state that the machine comprises a conveyor 11 of the endless belt type on which open glass jars 12 are deposited and moved from the entrance portal 13 to the exit portal 14. Surrounding the conveyor 11 is the housing which encloses a tunnel 16 through which the containers pass from the entrance to the exit portals. Sheet metal caps 17 are fed into the machine from a stack 18 along a downwardly inclined slide 19 which terminates in the tunnel and results in a cap being deposited on each container in order. After the cap is applied, it is pressed down by means of a belt 21 which is spring biased to force the cap over the container. It will be understood that the cap and container are suitably dimensioned, one with respect to the other so that the cap, which has a rubber sealing gasket, will securely fit on the container and seal the same hermetically.

In order to create a vacuum within the container, steam is caused to flow into the headspace. For such purpose a steam distributor 31 is installed above the tunnel to the entrance side of slide 19. One function of the steam distributor is to heat the caps and containers sufficiently so that the steam does not condense and unduly increase the percentage of water within the container. A further object of the steam distributor 31 is to cause a blanket or stratum of steam to flow diagonally, horizontally across the mouth of the container and the under-side of the cap to sweep away the air which is normally present. andv replace the air with steam. In order to prevent disturbance of the product in the containers, it is desirable that the steam be at low pressure and low velocity and in order to operate effectively it issfurther: desirablethatthe su'perheat of the steambe relatively high. The. details I ofthe structure whereby.

plate at its lower end'being spaced. slightly above the top; flight'of conveyor-l1 and'its-upperend and sides being-,attached to housing; 16% The platc is apertured in-- a shape 42complementary to the :shape of the container 12-being capped. Thereby, the 2 plate 41' reduces the airt which enters the tunnel.

Further to. prevent air from. entering the tunnel, a secondary steainpipe '43.-is.positioned at the top of the tunnel and immediatelyinsideportal 13. The steam emittedfrom pipe-M forms asteam barrier which flows outwardly through the-entrance portal 13 and by reason of the outward flow the: ingress of air is eliminated or reduced. Thus, the bathe-41 functions not only. to reduce ingress of air but also decreasesthe quantity; of steam required in that the area of the portal is reduced.

In the-constructioniofi the steam' distributor 31, the main steam supply enters through pipe 46 adjacent portal 13,v and, accordingly, the:interior of the steam distributor is largely filled with steam. The present invention employs-sufiicient steam toaheat the'distributor 31, the

slide-19 alongwhich-the caps enter-and the tunnel 16* throughzwhich'thejars enter, so asto prevent moisture condensation-in the-containers However, the quantity of steam is materially reduced.

Toreplace azlarge percentage of thesteam with nitrogen-or.other inert gas at the-zone in which the cap is applied, a pipe 47 isplaced insidethesteam distributor 31.-terminating:adjacent the-end of the distributor along which the cap slide 19 "is positioned. The'pipe 47 is connected-with a suitable source-of nitrogen or other inert gas under pressure and since the'main steam line 46 terminates-at-the entrance portal end of the steam distributort3l and'the'nitrogen line-47 terminates at the opposite':end,-the .balance ofadistribution ofthe steam and nitrogen in the steam distributor is, as shown in Fig. 3, preponderantly;nitrogenatthe point at which the caps are'applied. In'Fig; 3 the relative proportion of steam andz-nitrogendsschematically indicated by crosses for nitrogen anddotss-forsteam. The steam and nitrogen are directed'into' the tunnel along which the containers pass by means of thevanes 32, there being passageways (not shown inthe accompanying drawings but clearly illustrated in Patent 2,107,237) which conduct the-steam and nitrogen so that the entrance is horizontal and diagonal withwrespect toz'the' tops ofthe containers.

With the structure ishownf'in the accompanying drawings, approximately l it) cubic feet of steam per hour is introducedthrough'main steam line 46 and approximately' 160-cubic feet perhour of nitrogen is introduced throughzpipe-47. The secondary steam line '43 receives approximately 1,950- cubic-.feetper hour. Afterthe containers arev capped and cooled; the vacuum 'in' the container measures*19.5 inches of mercury. Analysis of the atmosphere in the headspaceshows 94% nitrogen andz4% oxygen. Since the nitrogen hasrno deleterious effect upon-the color or taste offtheproduct, its presence may bezdisregardeda and :thus the equivalent vacuumis 29.4- inches; whereas the actual vacuum is 19.5 inches.

ln 'addition; the actual amount of oxygen'present in the. headspaceiis reducedover thatin .a container having normali headspace at 'a vacuum of "29 inches.

Accordingly, the present invention'results ina-redu'cboiling which occurs as the containers cool after retorttion in the vacuum in the headspace. This reduces the ing and hence reduces starch break-down and weeping in the final product. In addition, where fruits are processed, the gas cells in the pulp of the fruit are not expanded and hence the layering efiect and rising of the pulp in the jar is eliminated; At the same time the absence of'oxygen. in the headspace reduces discoloration and improves the flavor. The-containers packaged in accordance with this invention may be filled with the normal headspace for which the containers are designed and it is unnecessary to overfill the containers." Thus the quantity. of material-required to fill a given container is reduced. In addition, the disadvantages inherent in the spillage which occurs when the containers are over-filled are eliminated.

Although lhave described-the invention in somedetail by way, of illustration and example for purposes of clarity of understanding, it is understood that certain changes and modifications may be practiced within the spirit of-the invention and scope of the appended claims.

What is claimedisz 1. In a container-sealing apparatus of the-type wherein is provided a tunnel, a conveyor for advancing containers through said tunnel, a slide for container'closures positionedto convey-closuresinto said tunnel and deposit a closureon an opencontainer and a pressing: device for seatinga closure on a container, the improvement comprising a steamandinert gas distributor positioned in the toprof-saidtunnel between the entrance of said tunnel andsaid slide, said' distributor being formed with discharge outlets to-direct steam and inert gas into an open top containermoving along said conveyor and sweep the air therefrom, asteam inlet pipe'connected to the interior-of said distributor, a source of steam for said steam inlet pipe, 21 separateinert gas inlet pipe connected to the interiorofsaiddistributor, and 'asource'of inert gas for. saidinert gas inlet pipe, said steam inlet pipe terminatingin said steam distributor adjacent a point above -theentrance-of said tunnel and the inert gas inlet pipe terminating in said steam distributor adjacent said slide.

2. The'improvement' defined in claim -1 which further comprisesa secondary steaminlet line terminating in said tunnel adjacent the entrance thereof.

3. Theimprovement defined in claim 2 which further comprises a baffle plate over the entrance of said tunnel comprises-driving the air from the headspace of the-con-- tainer byiflowing-a low pressure, lowvelocity mixture of steam'andinertgas over the-top of said-container in which-the-steam-in said-mixture predominates, filling theheadspace with amixture of steam and inert gas in which said inert gas predominates and-sealing-said container, the proportions of said mixture being such that at room temperature the -vacuum in said headspace is approximately inches andthe oxygen approximately 4%.

References Ci ted in the file of this patent UNITED STATES PATENTS Davies Hdhli. Mar. 10, 1953 Davies Feb. 1, 1938' May 18, 1943- 

4. A METHOD OF SEALING CONTAINERS UNDER RELATIVELY LOW VACUUM AND IN THE PRESENCE OF A REDUCED AMOUNT OF OXYGEN COMPRISING FILLING SAID CONTAINER WITH NORMAL HEADSPACE, SPREADING A STRATUM OF STEAM AND INERT GAS AT LOW PRESSURE AND LOW VELOCITY OVER THE TOP OF THE CONTAINER TO DRIVE OUT AIR FROM THE HEADSPACE AND FILL THE HEADSPACE WITH A MIXTURE OF STREAM AND INERT GAS, APPLYING A CLOSURE TO SAID CONTAINER, AND SEALING SAID CLOSURE, SAID METHOD BEING CHARACTERIZED BY THE FACT THAT DURING THE SPREADING STEP SAID STRATUM IS INITIALLY PREDOMINANTLY STEAM AND THEN PREDOMINANTLY INERT GAS. 